LAUSR

Abstract In the current investigation, a surface elastic-based three-dimensional (3D) nonlinear formulation is provided to explore the thermal postbuckling characteristics of porous composite nanoplates made of a functionally graded material (FGM) having a central cutout with different shapes. The surface stress factors are taken into the formulation by choosing the Gurtin-Murdoch theory of elasticity within the framework of a hybrid-type quasi-3D higher-order plate theory. With the aid of the isogeometric solving process using non-uniform rational B-splines as the basis functions, higher-order approximation with a precise geometric modelling of the structure is achieved. In the context of a refined power-law function together with the Touloukian scheme, the porosity-dependent as well as temperature-dependent material properties are achieved. It is portrayed that for a higher value of the material gradient index, the role of surface stress type of size dependency in the thermal postbuckling of porous FGM nanoplates becomes more important. Furthermore, it is deduced that by going to deeper part of the postbuckling regime which results in a higher value of the maximum deflection, the increment in the associated temperature rise caused by the surface stress size effect reduces. Also, it is found that by considering a higher value of the maximum deflection and moving to deeper region of the postbuckling domain, the existence of a central cutout leads to change the trend of the thermal postbuckling equilibrium path especially for a bigger central cutout.